The present invention relates to a method for controlling a data processing device that is connected to a computer via an interface. Standard computer operating systems prevent direct access by application programs to existing hardware or attached devices. Typically, the operating system manages the hardware and the devices and makes available operating functions to the application program for its use. This is done for the reasons of stability and security. In this way, it is impossible, for example, to incorrectly write the contents of mass-storage devices, for example, a hard drive, through an incorrectly operating application program.
Specific operations and commands, like the direct access to a device, for example, via “SCSI pass-through” or “USB low-level” connections, are restricted. Either access is reserved for the administrators of the operating system or access is controlled and monitored by special device drivers. However, device drivers can be installed on the computer only with administrator rights of the operating system.
These restrictions have a disadvantageous effect for the normal user who would like to access and use a device. When a typical user connects a device to a computer, he always requires administrator rights to be able to access the device; this is applicable at least at the first access, when the special device driver is to be installed and started for the first time. However, most users are not given these administrator rights. Even for publicly accessible computers or computers installed in a company-wide network, the rights of normal users or guest users are strictly limited. Thus, the access and use of devices which are connected to a computer via an interface are also automatically limited.
For access to files, however, usually no administrator rights are required. To write or save a file onto an internal or external storage medium or to read or restore the file from this storage medium, the access rights of a normal user, usually even the rights of a guest user, are sufficient. This is applicable especially when the user himself is the owner of the storage medium.
However, usually the normal user is not permitted to execute other computer commands besides writing or reading from files. The greater the engagement of the computer command to be executed to the contents of the hardware or connected devices and the more the command engages the file management system of the computer, the more exclusive is the execution of such a command. Only persons with special rights can execute such commands; certain critical commands are even reserved exclusively to the administrator.
Thus, there can be accomplished task of communicating through a computer with a connected data processing device and allowing commands and instructions to be executed on this computer, without expanding or changing the operating system of the computer or without installing a special driver, which first makes the access to the connected device possible.